In a ball screw mechanism, rotation of a screw is converted to linear motion of a nut encircling the screw. The screw and nut define respective, aligned helical grooves and a plurality of balls move in the grooves. The path defined by the respective grooves is called the mesh of the ball screw mechanism. The force transfer from screw to the nut occurs across the balls. In most ball screws, the extent of linear travel of the nut requires that balls moving in the mesh must exit at one end of the mechanism and re-enter the mesh at a second end. The balls are directed to the second end of the mechanism for re-entry into the mesh. A return guide is engaged with the nut to define a return path along which the plurality of balls move between the first and second ends.